Chapter 13. Memory, Learning, and Development
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By JANE E. BRODY As a woman of a certain age who consumes a well-balanced diet of all the usual food groups, including reasonable amounts of animal protein, I tend to dismiss advice to take a multivitamin supplement. I’ve been told repeatedly by nutrition experts that the overuse of dietary supplements for “nutritional insurance” has given Americans the most expensive urine in the world. I do take a daily supplement of vitamin D, based on considerable evidence of its multiple health benefits, especially for older people. However, based on advice from the National Academy of Medicine and an examination of accumulating research, I’m prompted to consider also taking a vitamin B12 supplement in hopes of protecting my aging brain. Animal protein foods — meat, fish, milk, cheese and eggs — are the only reliable natural dietary sources of B12, and I do get ample amounts of several in my regular diet. But now at age 75, I wonder whether I’m still able to reap the full benefit of what I ingest. You see, the ability to absorb B12 naturally present in foods depends on the presence of adequate stomach acid, the enzyme pepsin and a gastric protein called intrinsic factor to release the vitamin from the food protein it is attached to. Only then can the vitamin be absorbed by the small intestine. As people age, acid-producing cells in the stomach may gradually cease to function, a condition called atrophic gastritis. A century ago, researchers discovered that some people — most likely including Mary Todd Lincoln — had a condition called pernicious anemia, a deficiency of red blood cells ultimately identified as an autoimmune disease that causes a loss of stomach cells needed for B12 absorption. Mrs. Lincoln was known to behave erratically and was ultimately committed to a mental hospital. © 2016 The New York Times Company
Keyword: Development of the Brain
Link ID: 22634 - Posted: 09.06.2016
By Jesse Singal Back in 2014, a bigoted African leader put J. Michael Bailey, a psychologist at Northwestern, in a strange position. Yoweri Museveni, the president of Uganda, had been issuing a series of anti-gay tirades, and — partially fueled by anti-gay religious figures from the U.S. — was considering toughening Uganda’s anti-gay laws. The rhetoric was getting out of control: “The commercialisation of homosexuality is unacceptable,” said Simon Lokodo, Uganda’s ethics minister. “If they were doing it in their own rooms we wouldn’t mind, but when they go for children, that’s not fair. They are beasts of the forest.” Eventually, Museveni said he would table the idea of new legislation until he better understood the science of homosexuality, and agreed to lay off Uganda’s LGBT population if someone could prove to him homosexuality was innate. That’s where Bailey comes in: He’s a leading sex researcher who has published at length on the question of where sexual orientation comes from. LGBT advocates began reaching out to him to explain the science of homosexuality and, presumably, denounce Museveni for his hateful rhetoric. But “I had issues with rushing out a scientific statement that homosexuality is innate,” he said in an email, because he’s not sure that’s quite accurate. While he did write articles, such as an editorial in New Scientist, explaining why he thought Museveni’s position didn’t make sense, he stopped short of calling homosexuality innate. He also realized that in light of some recent advances in the science of sexual orientation, it was time to publish an article summing up the current state of the field — gathering together all that was broadly agreed-upon about the nature and potential origins of sexual orientation. (In the meantime, Museveni did end up signing the anti-gay legislation, justifying his decision by reasoning that homosexuality “was learned and could be unlearned.”) © 2016, New York Media LLC.
Laura Sanders An experimental drug swept sticky plaques from the brains of a small number of people with Alzheimer’s disease over the course of a year. And preliminary results hint that this cleanup may have staved off mental decline. News about the new drug, an antibody called aducanumab, led to excitement as it trickled out of recent scientific meetings. A paper published online August 31 in Nature offers a more comprehensive look at the drug’s effects. “Overall, this is the best news that we’ve had in my 25 years doing Alzheimer’s clinical research,” study coauthor Stephen Salloway of Brown University said August 30 at a news briefing. “It brings new hope for patients and families most affected by the disease.” The results are the most convincing evidence yet that an antibody can reduce amyloid in the brain, says Alzheimer’s researcherRachelle Doody of Baylor College of Medicine in Houston, who was not involved in the study. Still, experts caution that the results come from 165 people, a relatively small number. The seemingly beneficial effects could disappear in larger clinical trials, which are under way. “These new data are tantalizing, but they are not yet definitive,” says neuroscientist John Hardy of University College London. Like some other drug candidates for Alzheimer’s, aducanumab is an antibody that targets amyloid-beta, a sticky protein that accumulates in the brains of people with the disease. Delivered by intravenous injection, aducanumab appeared to get inside the brains of people with mild Alzheimer’s (average age about 73) and destroy A-beta plaques, the results suggest. After a year of exposure to the drug, A-beta levels had dropped. This reduction depended on the dose — the more drug, the bigger the decline in A-beta. In fact, people on the highest dose of the drug had almost no A-beta plaques in their brains after a year. |© Society for Science & the Public 2000 - 2016.
Link ID: 22621 - Posted: 09.01.2016
Merrit Kennedy More than 1,000 residents of a public housing complex in East Chicago, Ind., are now forced to relocate because of dangerously high lead levels in the area's soil. The West Calumet Housing Complex, which houses primarily low-income families, lies on the site of a former lead smelting company, as member station WBEZ reported. In July, the Environmental Protection Agency reported high lead levels in the soil in parts of the complex and notified the residents. The EPA advised parents to stop their kids from playing in the dirt, "to wash their children's toys regularly and to wash children's hands after they play outside." As WBEZ reported, the samples showed lead levels "three times higher than the federal safety standards and in some places even higher, much higher." After that, East Chicago Mayor Anthony Copeland "ordered the removal of 1,200 residents from the West Calumet housing project for safety concerns," according to the member station. The residents have now been informed that the 346-unit complex is set to be demolished. "Residents have been provided vouchers for temporary hotel living until their homes are done being cleaned. The residents will return to their homes for a few more months until vouchers for permanent housing are made available by the U.S. Department of Housing and Urban Development." © 2016 npr
By Amy Ellis Nutt Before iPhones and thumb drives, before Google docs and gigabytes of RAM, memory was more art than artifact. It wasn’t a tool or a byproduct of being human. It was essential to our character and therefore a powerful theme in both myth and literature. At the end of Book 2 of the “Divine Comedy,” with Paradise nearly in reach, Dante is dipped into the River Lethe, where the sins of the self are washed away in the waters of forgetfulness. To be truly cleansed of his memories, however, Dante must also drink from the river of oblivion. Only then will he be truly purified and the memories of his good deeds restored to him. Before we can truly remember, according to Dante, we must forget. In “Patient H.M.: A Story of Memory, Madness, and Family Secrets,” author Luke Dittrich seems to be saying that before we can forgive, we must remember. The terrible irony is that H.M., the real-life character around whom Dittrich’s book revolves, had no memory at all. In prose both elegant and intimate, and often thrilling, “Patient H.M.” is an important book about the wages not of sin but of science. It is deeply reported and surprisingly emotional, at times poignant, at others shocking. H.M., arguably the single most important research subject in the history of neuroscience, was once Henry Molaison, an ordinary New England boy. When Henry was 9 years old, he was hit by a bicyclist as he walked across the street in his home town, Hartford, Conn. © 1996-2016 The Washington Post
Keyword: Learning & Memory
Link ID: 22604 - Posted: 08.27.2016
Nicola Davis Children who suffer a traumatic brain injury, including mild concussion from a blow to the head, are less likely to do well at school and are at increased risk of early death, researchers have revealed. As adults they are also more likely to receive a disability pension, have failed to gain secondary school qualifications and nearly twice as likely to have been hospitalised for psychiatric reasons. The team analysed data from more than a million people born between 1973 and 1985, finding that around 9% had been diagnosed with at least one traumatic brain injury before the age of 25. More than 75% of these were mild injuries. The researchers compared the outcomes for these individuals with those of others who had not experienced a head injury, as well as carrying out a second comparison, where possible, with siblings who had not been injured. Once factors such as age and sex were taken into account, the team found that those diagnosed with a traumatic brain injury have an increased risk of experiencing a number of health and social problems. Those who had suffered a traumatic brain injury were 76% more likely to receive a disability pension, 58% more likely to have failed to gain secondary school qualifications and nearly twice as likely to have been hospitalised for psychiatric reasons, compared to those who had sustained no injury. When the researchers looked at patients who had siblings that had not sustained a traumatic brain injury, they found similar - although smaller - effects, suggesting that genetics could also play a role. © 2016 Guardian News and Media Limited
By PAM BELLUCK The images tell a heartbreaking story: Zika’s calamitous attack on the brains of babies — as seen from the inside. A study of brain scans and ultrasound pictures of 45 Brazilian babies whose mothers were infected with Zika in pregnancy shows that the virus can inflict serious damage to many different parts of the fetal brain beyond microcephaly, the condition of unusually small heads that has become the sinister signature of Zika. The images, published Tuesday in the journal Radiology, also suggest a grim possibility: Because some of the damage was seen in brain areas that continue to develop after birth, it may be that babies born without obvious impairment will experience problems as they grow. “It really brings to the forefront the importance of truly understanding the impact of Zika virus and the fact that we need to follow children who not only are exposed to Zika in pregnancy, but even those who don’t appear to have any complications at birth,” said Dr. Catherine Y. Spong, chief of the pregnancy and perinatology branch of the Eunice Kennedy Shriver National Institute of Child Health and Human Development, who was not involved in the study. Most of the babies in the study were born with microcephaly, although three were not. Each also suffered other impairments, almost all of which emerge earlier than microcephaly because a smaller head is really a consequence of brain that has failed to develop fully or has been damaged along the way, experts said. “The brain that should be there is not there,” said Dr. Deborah Levine, an author of the study and a professor of radiology at Harvard Medical School in Boston. “The abnormalities that we see in the brain suggest a very early disruption of the brain development process.” © 2016 The New York Times Company
Keyword: Development of the Brain
Link ID: 22594 - Posted: 08.24.2016
Ian Sample Science editor For Jules Verne it was the friend who keeps us waiting. For Edgar Allan Poe so many little slices of death. But though the reason we spend a third of our lives asleep has so far resisted scientific explanation, research into the impact of sleepless nights on brain function has shed fresh light on the mystery - and also offered intriguing clues to potential treatments for depression. In a study published on Tuesday, researchers show for the first time that sleep resets the steady build-up of connectivity in the human brain which takes place in our waking hours. The process appears to be crucial for our brains to remember and learn so we can adapt to the world around us. The loss of a single night’s sleep was enough to block the brain’s natural reset mechanism, the scientists found. Deprived of rest, the brain’s neurons seemingly became over-connected and so muddled with electrical activity that new memories could not be properly laid down. Lack of sleep alters brain chemicals to bring on cannabis-style 'munchies' But Christoph Nissen, a psychiatrist who led the study at the University of Freiburg, is also excited about the potential for helping people with mental health disorders. One radical treatment for major depression is therapeutic sleep deprivation, which Nissen believes works through changing the patient’s brain connectivity. The new research offers a deeper understanding of the phenomenon which could be adapted to produce more practical treatments. © 2016 Guardian News and Media Limited
Scientists and clinicians have long dreamed of helping the injured brain repair itself by creating new neurons, and an innovative NIH-funded study published today in Nature Medicine may bring this goal much closer to reality. A team of researchers has developed a therapeutic technique that dramatically increases the production of nerve cells in mice with stroke-induced brain damage. The therapy relies on the combination of two methods that show promise as treatments for stroke-induced neurological injury. The first consists of surgically grafting human neural stem cells into the damaged area, where they mature into neurons and other brain cells. The second involves administering a compound called 3K3A-APC, which the scientists have shown helps neural stem cells grown in a petri dish develop into neurons. However, it was unclear what effect the molecule, derived from a human protein called activated protein-C (APC), would have in live animals. A month after their strokes, mice that had received both the stem cells and 3K3A-APC performed significantly better on tests of motor and sensory functions compared to mice that received neither or only one of the treatments. In addition, many more of the stem cells survived and matured into neurons in the mice given 3K3A-APC. “This USC-led animal study could pave the way for a potential breakthrough in how we treat people who have experienced a stroke,” added Jim Koenig, Ph.D., a program director at the NIH’s National Institute of Neurological Disorders and Stroke (NINDS), which funded the research. “If the therapy works in humans, it could markedly accelerate the recovery of these patients.”
By Clare Wilson Taking a daily vitamin or mineral supplement is widely seen as a common-sense way of looking after yourself – a kind of insurance, like wearing a seat belt. But evidence is growing that it might not be such a healthy habit after all. The latest finding is that calcium supplements, taken by many women after the menopause to strengthen their bones, are linked to dementia. Among women who have had a stroke, taking calcium was associated with a seven-fold rise in the number who went on to have dementia. Calcium was also linked with a smaller, non-statistically significant, rise in dementia in women who had not had a stroke. The finding emerged from a study that was not a randomised trial, so it is not the most robust type of medical evidence. The researchers merely counted dementia cases in people who had chosen whether to take calcium, and so the data could be biased. But the results are striking and come on the heels of a previous study that was a randomised trial, which found a link between calcium supplements and a modestly higher risk of heart attacks – suggesting that caution over calcium is indeed warranted. If future research confirms the association with dementia, women would face a horrible dilemma: should they continue to take calcium, staving off bone weakness that can lead to fatal hip fractures, while running an increased risk of one of the most dreaded illness of ageing? So what’s going on? Team member Silke Kern at the Sahlgrenska Academy Institute of Neuroscience and Physiology in Gothenburg, Sweden, says that taking a calcium pill triggers a rapid surge in the mineral’s levels in the blood, one that you wouldn’t get from calcium in food. © Copyright Reed Business Information Ltd.
Link ID: 22588 - Posted: 08.23.2016
By KATHERINE KINZLER You may not be surprised to learn that food preference is a social matter. What we choose to eat depends on more than just what tastes good or is healthful. People in different cultures eat different things, and within a culture, what you eat can signal something about who you are. More surprising is that the sociality of food selection, it turns out, runs deep in human nature. In research published this month in the Proceedings of the National Academy of Sciences, my colleagues and I showed that even 1-year-old babies understand that people’s food preferences depend on their social or cultural group. Interestingly, we found that babies’ thinking about food preferences isn’t really about food per se. It’s more about the people eating foods, and the relationship between food choice and social groups. While it’s hard to know what babies think before they can talk, developmental psychologists have long capitalized on the fact that babies’ visual gaze is guided by their interest. Babies tend to look longer at something that is novel or surprising. Do something bizarre the next time you meet a baby, and you’ll notice her looking intently. Using this method, the psychologists Zoe Liberman, Amanda Woodward, Kathleen Sullivan and I conducted a series of studies. Led by Professor Liberman, we brought more than 200 1-year-olds (and their parents) into a developmental psychology lab, and showed them videos of people visibly expressing like or dislike of foods. For instance, one group of babies saw a video of a person who ate a food and expressed that she loved it. Next they saw a video of a second person who tried the same food and also loved it. This second event was not terribly surprising to the babies: The two people agreed, after all. Accordingly, the babies did not look for very long at this second video; it was what they expected. © 2016 The New York Times Company
By Virginia Morell Scientists have long worried whether animals can respond to the planet’s changing climate. Now, a new study reports that at least one species of songbird—and likely many more—already knows how to prep its chicks for a warming world. They do so by emitting special calls to the embryos inside their eggs, which can hear and learn external sounds. This is the first time scientists have found animals using sound to affect the growth, development, behavior, and reproductive success of their offspring, and adds to a growing body of research revealing that birds can “doctor” their eggs. “The study is novel, surprising, and fascinating, and is sure to lead to much more work on parent-embryo communication,” says Robert Magrath, a behavioral ecologist at the Australian National University in Canberra who was not involved in the study. The idea that the zebra finch (Taeniopygia guttata) parents were “talking to their eggs” occurred to Mylene Mariette, a behavioral ecologist at Deakin University in Waurn Ponds, Australia, while recording the birds’ sounds at an outdoor aviary. She noticed that sometimes when a parent was alone, it would make a rapid, high-pitched series of calls while sitting on the eggs. Mariette and her co-author, Katherine Buchanan, recorded the incubation calls of 61 female and 61 male finches inside the aviary. They found that parents of both sexes uttered these calls only during the end of the incubation period and when the maximum daily temperature rose above 26°C (78.8°F). © 2016 American Association for the Advancement of Scienc
By Emily Underwood In 2010, neurobiologist Beth Stevens had completed a remarkable rise from laboratory technician to star researcher. Then 40, she was in her second year as a principal investigator at Boston Children’s Hospital with a joint faculty position at Harvard Medical School. She had a sleek, newly built lab and a team of eager postdoctoral investigators. Her credentials were impeccable, with high-profile collaborators and her name on an impressive number of papers in well-respected journals. But like many young researchers, Stevens feared she was on the brink of scientific failure. Rather than choosing a small, manageable project, she had set her sights on tackling an ambitious, unifying hypothesis linking the brain and the immune system to explain both normal brain development and disease. Although the preliminary data she’d gathered as a postdoc at Stanford University in Palo Alto, California, were promising, their implications were still murky. “I thought, ‘What if my model is just a model, and I let all these people down?’” she says. Stevens, along with her mentor at Stanford, Ben Barres, had proposed that brain cells called microglia prune neuronal connections during embryonic and later development in response to a signal from a branch of the immune system known as the classical complement pathway. If a glitch in the complement system causes microglia to prune too many or too few connections, called synapses, they’d hypothesized, it could lead to both developmental and degenerative disorders. © 2016 American Association for the Advancement of Science.
Meghan Rosen Zika may harm grown-up brains. The virus, which can cause brain damage in infants infected in the womb, kills stem cells and stunts their numbers in the brains of adult mice, researchers report August 18 in Cell Stem Cell. Though scientists have considered Zika primarily a threat to unborn babies, the new findings suggest that the virus may cause unknown — and potentially long-term — damage to adults as well. In adults, Zika has been linked to Guillain-Barré syndrome, a rare neurological disorder (SN: 4/2/16, p. 29). But for most people, infection is typically mild: a headache, fever and rash lasting up to a week, or no symptoms at all. In pregnant women, though, the virus can lodge in the brain of a fetus and kill off newly developing cells (SN: 4/13/16). If Zika targets newborn brain cells, adults may be at risk, too, reasoned neuroscientist Joseph Gleeson of Rockefeller University in New York City and colleagues. Parts of the forebrain and the hippocampus, which plays a crucial role in learning and memory, continue to generate nerve cells in adult brains. In mice infected with Zika, the virus hit these brain regions hard. Nerve cells died and the regions generated one-fifth to one-half as many new cells compared with those of uninfected mice. The results might not translate to humans; the mice were genetically engineered to have weak immune systems, making them susceptible to Zika. But Zika could potentially harm immunocompromised people and perhaps even healthy people in a similar way, the authors write. © Society for Science & the Public 2000 - 2016.
Keyword: Development of the Brain
Link ID: 22575 - Posted: 08.20.2016
By Nicholas Bakalar Taking antipsychotic medicines during pregnancy does not increase the risk for birth defects, a large new study has found. Antipsychotics are used to treat schizophrenia, bipolar disorder, depression and other psychiatric disorders. Previous studies of their use during pregnancy have been small and have had mixed results. This study, in JAMA Psychiatry, reviewed records of 1,341,715 pregnant women, of whom 9,258 filled prescriptions for the newer atypical antipsychotics like quetiapine (Seroquel) or aripiprazole (Abilify), and 733 for older typical antipsychotics such as haloperidol (Haldol). All prescriptions were filled in the first trimester of pregnancy. After controlling for race, number of pregnancies, smoking, alcohol use, psychiatric conditions, additional medications and other variables, there was no difference in the risk for birth defects between those who took the drugs and those who did not. One possible exception was a marginal increase in risk with one drug, risperidone (Risperdal), which the authors said will require further study. “These findings suggest that the use of antipsychotics during the first trimester does not seem to increase congenital malformation,” or birth defects, said the lead author, Krista F. Huybrechts, an assistant professor of medicine at Harvard. But, she added, “we only looked at congenital malformation, not other possible negative outcomes for women and their children.” © 2016 The New York Times Company
By Jessica Hamzelou Feel like you’ve read this before? Most of us have experienced the eerie familiarity of déjà vu, and now the first brain scans of this phenomenon have revealed why – it’s a sign of our brain checking its memory. Déjà vu was thought to be caused by the brain making false memories, but research by Akira O’Connor at the University of St Andrews, UK, and his team now suggests this is wrong. Exactly how déjà vu works has long been a mystery, partly because its fleeting and unpredictable nature makes it difficult to study. To get around this, O’Connor and his colleagues developed a way to trigger the sensation of déjà vu in the lab. The team’s technique uses a standard method to trigger false memories. It involves telling a person a list of related words – such as bed, pillow, night, dream – but not the key word linking them together, in this case, sleep. When the person is later quizzed on the words they’ve heard, they tend to believe they have also heard “sleep” – a false memory. To create the feeling of déjà vu, O’ Connor’s team first asked people if they had heard any words beginning with the letter “s”. The volunteers replied that they hadn’t. This meant that when they were later asked if they had heard the word sleep, they were able to remember that they couldn’t have, but at the same time, the word felt familiar. “They report having this strange experience of déjà vu,” says O’Connor. © Copyright Reed Business Information Ltd.
By Roni Caryn Rabin Dementia is a general term for a set of symptoms that includes severe memory loss, a significant decline in reasoning and severely impaired communication skills; it most commonly strikes elderly people and used to be referred to as “senility.” Alzheimer’s disease is a specific illness that is the most common cause of dementia. Though many diseases can cause dementia, Alzheimer’s accounts for 60 percent to 80 percent of dementia cases, “which is why you’ll often hear the terms used interchangeably,” said Heather Snyder, the senior director of medical and scientific operations for the Alzheimer’s Association. She said the question comes up frequently because patients may receive an initial diagnosis of dementia followed by an evaluation that yields the more specific diagnosis of Alzheimer’s disease, and they may be confused. The second most common form of dementia is vascular dementia, which is caused by a stroke or poor blood flow to the brain. Other diseases that can lead to dementia include Huntington’s disease, Parkinson’s disease and Creutzfeldt-Jakob disease. Some patients may have more than one form of dementia. Dementia is caused by damage to brain cells. In the case of Alzheimer’s disease, that damage is characterized by telltale protein fragments or plaques that accumulate in the space between nerve cells and twisted tangles of another protein that build up inside cells. In Alzheimer’s disease, dementia gets progressively worse to the point where patients cannot carry out daily activities and cannot speak, respond to their environment, swallow or walk. Although some treatments may temporarily ease symptoms, the downward progression of disease continues and it is not curable. © 2016 The New York Times Company
Link ID: 22559 - Posted: 08.16.2016
By Anna Azvolinsky Sets of neurons in the brain that behave together—firing synchronously in response to sensory or motor stimuli—are thought to be functionally and physiologically connected. These naturally occurring ensembles of neurons are one of the ways memories may be programmed in the brain. Now, in a paper published today (August 11) in Science, researchers at Columbia University and their colleagues show that it is possible to stimulate visual cortex neurons in living, awake mice and induce a new ensemble of neurons that behave as a group and maintain their concerted firing for several days. “This work takes the concept of correlated [neuronal] firing patterns in a new and important causal direction,” David Kleinfeld, a neurophysicist at the University of California, San Diego, who was not involved in the work told The Scientist. “In a sense, [the researchers] created a memory for a visual feature that does not exist in the physical world as a proof of principal of how real visual memories are formed.” “Researchers have previously related optogenetic stimulation to behavior [in animals], but this study breaks new ground by investigating the dynamics of neural activity in relation to the ensemble to which these neurons belong,” said Sebastian Seung, a computational neuroscientist at the Princeton Neuroscience Institute in New Jersey who also was not involved in the study. Columbia’s Rafael Yuste and colleagues stimulated randomly selected sets of individual neurons in the visual cortices of living mice using two-photon stimulation while the animals ran on a treadmill. © 1986-2016 The Scientist
David R. Jacobs, We all know that exercise improves our physical fitness, but staying in shape can also boost our brainpower. We are not entirely sure how, but evidence points to several explanations. First, to maintain normal cognitive function, the brain requires a constant supply of oxygen and other chemicals, delivered via its abundant blood vessels. Physical exercise—and even just simple activities such as washing dishes or vacuuming—helps to circulate nutrient-rich blood efficiently throughout the body and keeps the blood vessels healthy. Exercise increases the creation of mitochondria—the cellular structures that generate and maintain our energy—both in our muscles and in our brain, which may explain the mental edge we often experience after a workout. Studies also show that getting the heart rate up enhances neurogenesis—the ability to grow new brain cells—in adults. Regardless of the mechanism, mounting evidence is revealing a robust relation between physical fitness and cognitive function. In our 2014 study, published in Neurology, we found that physical activity has an extensive, long-lasting influence on cognitive performance. We followed 2,747 healthy people between the ages of 18 and 30 for 25 years. In 1985 we evaluated their physical fitness using a treadmill test: the participants walked up an incline that became increasingly steep every two minutes. On average, they walked for about 10 minutes, reaching 3.4 miles per hour at an 18 percent incline (a fairly steep hill). Low performers lasted for only seven minutes and high performers for about 13 minutes. A second treadmill test in 2005 revealed that our participants' fitness levels had declined with age, as would be expected, but those who were in better shape in 1985 were also more likely to be fit 20 years later. © 2016 Scientific American
Link ID: 22555 - Posted: 08.13.2016
Ed Yong At the age of seven, Henry Gustav Molaison was involved in an accident that left him with severe epilepsy. Twenty years later, a surgeon named William Scoville tried to cure him by removing parts of his brain. It worked, but the procedure left Molaison unable to make new long-term memories. Everyone he met, every conversation he had, everything that happened to him would just evaporate from his mind. These problems revolutionized our understanding of how memory works, and transformed Molaison into “Patient H.M.”—arguably the most famous and studied patient in the history of neuroscience. That’s the familiar version of the story, but the one presented in Luke Dittrich’s new book Patient H.M.: A Story of Memory, Madness, and Family Secrets is deeper and darker. As revealed through Dittrich’s extensive reporting and poetic prose, Molaison’s tale is one of ethical dilemmas that not only influenced his famous surgery but persisted well beyond his death in 2008. It’s a story about more than just the life of one man or the root of memory; it’s also about how far people are willing to go for scientific advancement, and the human cost of that progress. And Dittrich is uniquely placed to consider these issues. Scoville was his grandfather. Suzanne Corkin, the scientist who worked with Molaison most extensively after his surgery, was an old friend of his mother’s. I spoke to him about the book and the challenges of reporting a story that he was so deeply entwined in. Most of this interview was conducted on July 19th. Following a New York Times excerpt published on August 7th, and the book’s release two weeks later, many neuroscientists have expressed “outrage” at Dittrich’s portrayal of Corkin. The controversy culminated in a statement from MIT, where Corkin was based, rebutting three allegations in the book. Dittrich has himself responded to the rebuttals, and at the end of this interview, I talk to him about the debate. © 2016 by The Atlantic Monthly Group.
Keyword: Learning & Memory
Link ID: 22552 - Posted: 08.13.2016